Sunday, January 22, 2017

Enteroviruses may be linked to increased type I diabetes risk

Researchers in Finland are contributing to a growing body of
literature that suggests that enterovirus infections may be one of several
environmental triggers that cause type I diabetes. Their study showed that
children who were in the early stages of type I diabetes had a more remarkable
history for enterovirus infection than control children in the past year. The
study sample was composed of 129 children with multiple islet autoantibodies
and 282 children without autoantibodies. Scientists tested several stool
samples from children in both groups. They noted that the enterovirus
infections occurred more than a year before the islet autoantibodies developed,
which may indicate the time required for an enterovirus to elicit an autoimmune
response of the pancreas in genetically susceptible individuals.

I was skeptical of this finding since enterovirus infection
is extremely common and yet type I diabetes has a prevalence of 0.4% in the US.
So, I looked up an article in Pub Med Central that reported the history of
association between enterovirus and type 1 diabetes. Apparently, this
association has been around since the 1960s when Gamble et al reported seasonal
incidence of type I diabetes that paralleled enterovirus infection. Experiments
on mouse models do seem to provide compelling evidence of a causal link.
Several research groups have conducted serological and RT-PCR studies on people
with type I diabetes that reveal more enterovirus antibodies and RNA. Since the
majority of these studies are retrospective, they cannot determine causality.
Ultimately, the connection between enterovirus infection and type I diabetes is
weak.